The Crescentic Implication of Renal Outcomes in Proliferative Lupus Nephritis

Interstitial fibrosis increases the risk of end-stage kidney disease in patients with lupus nephritis

OBJECTIVE

To evaluate the risk of end-stage kidney disease (ESKD) in lupus nephritis (LN) patients using tubulointerstitial lesion scores.

METHODS

Clinical profiles and histopathological presentations of 151 biopsy-proven LN patients were retrospectively examined. Risk factors of ESKD based on characteristics and scoring of their tubulointerstitial lesions (e.g. interstitial inflammation [II], tubular atrophy [TA], and interstitial fibrosis [IF]) were analyzed.

RESULTS

The mean age of 151 LN patients was 36 years old, and 136 (90.1%) were female. The LN cases examined included: class I/II (n = 3, 2%), class III/IV (n = 119, 78.8%), class V (n = 23, 15.2%), and class VI (n = 6, 4.0%). The mean serum creatinine level was 1.4 mg/dl. Tubulointerstitial lesions were recorded in 120 (79.5%) patients. Prior to receiving renal biopsy, 9 (6.0%) patients developed ESKD. During the follow-up period (mean, 58 months), an additional 47 patients (31.1%) progressed to ESKD. Multivariate analyses identified serum creatinine (hazard ratio [HR]: 1.7, 95% confidence interval [CI]: 1.42-2.03, p < 0.001) and IF (HR: 3.2, 95% CI: 1.58-6.49, p = 0.001) as independent risk factors of ESKD. Kaplan-Meier analysis further confirmed a heightened risk of ESKD associated with IF.

CONCLUSION

Tubulointerstitial involvement is commonly observed in histopathological presentation of LN. However, IF, rather than II, or TA, was found to increase the risk of ESKD in our cohort. Therefore, to predict renal outcome in LN patients prior to adjusting immunosuppressive treatment, degree of IF should be reviewed.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND

In this study, we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis (LN) who underwent repeated renal biopsy.

CASE SUMMARY

Clinical data of three diffuse proliferative LN patients with different pathological characteristics (case 1 was LN IV-G (A), case 2 was LN IV-G (A) + V, and case 3 was LN IV-G (A) + thrombotic microangiopathy) were reviewed. All patients underwent repeated renal biopsies 6 mo later, and renal biopsy specimens were studied. Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining, and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage. After treatment, Case 1 changed to LN III-(A), Case 2 remained as type V LN lesions, and Case 3, which changed to LN IV-S (A), had the worst prognosis. We observed reduced macrophage infiltration after therapy. However, two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium. Before treatment, the three patients showed discontinuous expression of podocin. Notably, the integrity of podocin was restored after treatment in Case 1.

CONCLUSION

It may be possible to reverse podocyte damage and decrease the infiltrating macrophages in LN patients through effective treatment.

Renal Histopathology Associated With Kidney Failure and Mortality in Patients With Lupus Nephritis: A Long-Term Real-World Data Study

OBJECTIVE

Lupus nephritis (LN), a common manifestation of systemic lupus erythematosus, is associated with a higher risk of kidney failure and death. The renal pathology of LN helps elucidate the severity of inflammation and the extent of irreversible damage. We aimed to identify histologic variables that correlate with risks of kidney failure and mortality.

METHODS

Between 2006 and 2019, a total of 526 patients with LN were enrolled. Renal pathology was classified according to the International Society of Nephrology/Renal Pathology Society classification. Components of activity and chronicity indices were analyzed to determine which variables correlated with an increased risk of kidney failure and death, with the adjustment of potential confounders.

RESULTS

During the follow-up period (median 7.5, IQR 3.5-10.7 years), 58 patients progressed to kidney failure and 64 died. In the multivariate Cox regression analysis, tubular atrophy (hazard ratio [HR] 2.28, 95% CI 1.66-3.14) and tubulointerstitial inflammation (HR 3.13, 95% CI 1.34-7.33) predicted kidney failure. The renal outcome was even worse if tubular atrophy and tubulointerstitial inflammation coexisted (10-year kidney survival rate: 63.22%). The presence of cellular crescents was associated with an increased risk of death in male patients with LN (HR 1.91, 95% CI 1.02-3.57), whereas the presence of fibrous crescents predicted death in female patients with LN (HR 5.70, 95% CI 1.61-20.25).

CONCLUSION

Histologic variables of renal biopsy in LN could be regarded as prognostic indicators for kidney failure and mortality.

Role of crescents for lupus nephritis in clinical, pathological and prognosis: a single-center retrospective cohort study

BACKGROUND

Referring to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2018 pathological classification, we aim to reveal the significance of cellular/fibrocellular crescents in lupus nephritis (LN) patients.

METHODS

Patients with LN proven by renal biopsy at the First Affiliated Hospital of Wenzhou Medical University from December 2001 to November 2017 were identified, and eligible cases were divided into two groups according to the presence or absence of cellular/fibrocellular crescents in renal biopsy tissues.

RESULTS

A total of 401 LN patients were identified from our follow-up database, and 296 eligible LN patients were enrolled in the study. Of these patients, 146 patients in the group without cellular/fibrocellular crescents (non-crescent group) and 150 patients in the group with cellular/fibrocellular crescents (Crescent group). The median follow-up time of patients was 47 months, and a total of 54 patients progressed to the composite endpoint. Crescent group had higher serum creatinine, lower serum albumin, higher systemic lupus erythematosus (SLE) disease activity index, and higher activity index of renal tissue. The interaction between cellular/fibrocellular crescents and proteinuria at baseline was associated with the prognostic risk of LN (P = 0.006). In the group with proteinuria < 3.5 g/24 h, the prognosis of crescent group was significantly worse than of non-crescent group (P < 0.001), while in the group with proteinuria ≥ 3.5 g/24 h, there was no significant relationship between crescents and prognosis (p = 0.452). By multivariable Cox hazard analysis, positive anti-dsDNA, chronic index of renal biopsy tissue, cellular/fibrocellular crescents and its interaction with 24 h proteinuria were independent risk factors for poor prognosis of LN.

CONCLUSIONS

LN patients with cellular/fibrocellular crescents had more severe and active disease features, and cellular/fibrocellular crescents is a risk factor for poor prognosis of LN. There was an interaction between cellular/fibrocellular crescents and proteinuria in predicting poor prognosis, and among patients with low levels of proteinuria at the time of renal biopsy, those with crescents had a worse long-term prognosis than those without crescents.

Utility of the 2018 revised ISN/RPS thresholds for glomerular crescents in childhood-onset lupus nephritis: a Pediatric Nephrology Research Consortium study

BACKGROUND

The revised 2018 ISN/RPS Classification System for lupus nephritis (LN) includes calculations for both activity index (A.I.) and chronicity index (C.I.). Unchanged were the thresholds of < 25%, 25-50%, and > 50% crescents to distinguish between mild, moderate, and severe activity/chronicity. We aimed to evaluate these thresholds for percent crescents in childhood-onset LN.

METHODS

Eighty-six subjects < 21 years of age were enrolled from the Pediatric Glomerulonephritis with Crescents Registry, a retrospective multi-center cohort sponsored by the Pediatric Nephrology Research Consortium. Thresholds of 10%, 25%, and 50% for both cellular/fibrocellular and fibrous crescents were interrogated for primary outcomes of kidney failure, eGFR, and eGFR slope.

RESULTS

Median age at time of initial biopsy was 14 years (range 1-21). Median follow-up time was 3 years (range 1-11). Cumulative incidence of kidney failure was 6% at 1 year and 10% at latest follow-up. Median eGFR slope was - 18 mL/1.73 m²/min (IQR - 51 to + 8) at 1 year and - 3 mL/min/1.73 m²/year (IQR - 19 to + 6) at latest follow-up. We found no difference in kidney failure at the proposed < 25% and 25-50% cellular crescents thresholds, and thus added a new provisional threshold of 10% that better predicted outcomes in children. Moreover, use of 10% and 25% thresholds for fibrous crescents showed a fourfold and sevenfold increase in risk of kidney failure.

CONCLUSIONS

In children with crescentic LN, use of 10% and 25% thresholds for cellular crescents better reflects disease activity, while these thresholds for fibrous crescents better discriminates kidney disease outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

What do we actually know about exosomal microRNAs in kidney diseases?

There are several types of kidney diseases with complex causes. If left untreated, these diseases irreversibly progress to end-stage renal disease. Thus, their early diagnosis and targeted treatment are important. Exosomes—extracellular vesicles released by a variety of cells—are ideal carriers for DNA, RNA, proteins, and other metabolites owing to their bilayer membranes. Studies have shown that almost all renal cells can secrete exosomes. While research on exosomal microRNAs in the context of renal diseases begun only recently, rapid progress has been achieved. This review summarizes the changes in exosomal microRNA expression in different kidney diseases. Thus, it highlights the diagnostic and prognostic value of these exosomal microRNAs. Further, this review analyzes their roles in the development of different kidney diseases, guiding research on molecular mechanisms and therapeutic strategies.

Complement-mediated M2/M1 macrophage polarization may be involved in crescent formation in lupus nephritis

The function of the complement and macrophage crosstalk during the formation of crescents in lupus nephritis has not yet been reported. This study therefore aimed to explore the association of crescents, complements, and M2 macrophages with clinical features in lupus nephritis. We assessed a Chinese cohort comprising 301 patients with lupus nephritis. Renal biopsy specimens were collected from 64 patients with proliferative lupus nephritis (class III/III + V or IV/IV + V). The renal deposition of cluster of differentiation (CD) 68, inducible nitric oxide synthase, CD163, and C3a receptor (C3aR) was evaluated by immunostaining. The associations among crescents, complements, and M2 macrophages were also analyzed. Next, the underlying mechanism was investigated in vitro using C3a-treated macrophages. We found that M2-phenotype macrophages (CD163⁺) were the dominant subpopulation in human lupus nephritis. Additionally, a significant association was observed among the CD163⁺ macrophages, crescents, and complement activation. C3aR co-localized with CD163 and correlated with crescents and could induce polarization of macrophages to an M2 phenotype. Overall, these results suggest that complement-mediated M2/M1 macrophage polarization may contribute to the formation of crescents in lupus nephritis.

Clinical implication of the circumferential crescents lesions in immunoglobulin A nephropathy: a single-center study of Han Chinese population

A crescentic lesion in renal biopsy could be segmental or circumferential, but the distribution and clinical implication of the circumferential crescents in immunoglobulin A nephropathy (IgAN) remains unknown. A total of 384 crescentic IgAN patients between 2011 and 2019 were included. The subjects were classified as the circumferential crescent who have at least one crescent involving ≥50% circumference of Bowman's capsule, otherwise as to the segmental crescent. Clinical, pathological, and prognostic relationships were analyzed. The primary endpoint was a 30% decline in eGFR, and the secondary endpoint was more than 3.5 g/d proteinuria during follow-up. Of the 384 patients, 72 (18.8%) patients had more than one circumferential crescent. 52 (17.6%) Oxford C1 patients have circumferential crescent. During a mean follow-up of 32.3 months, both the primary and secondary endpoints have occurred more in the circumferential crescent patients. Kaplan-Meier analysis showed the patient with the circumferential crescent had significantly lower renal survival than those without. In multivariable Cox analyses, having the circumferential crescents in at least one-fifth of glomeruli was independently associated with primary endpoint (hazard ratio:3.60, 95% CI:1.46-8.83), after adjusting for Oxford-score, eGFR, systolic blood pressure, and proteinuria. Furthermore, those patients who scored C1 in Oxford and presenting with circumferential crescents, had better renal survival if they received the other immunosuppressants therapy. The circumferential crescents lesion was associated with adverse outcomes in IgAN, and more than one-fifth of glomeruli circumferential crescents is an independent predictor of 30% eGFR decline after adjusting for clinical and histological parameters.

Performance of the 2019 EULAR/ACR systemic lupus erythematosus classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis

Objective

To evaluate the performance of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) SLE classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis (LN) and their renal prognosis.

Methods

Patients with newly diagnosed SLE attending and followed up for >12 months were included. A retrospective review of all patients with renal biopsy fulfilling a consensus expert opinion during 2014 and 2018. Clinical, serological and pathological data were collected and each patient was assigned a high/low criteria scores (HS/LS) group. Survival curves for flare adjusted for multiplicity on renal flares, was applied to the two groups.

Results

Applying EULAR/ACR criteria in our cohort of 126 patients, 6 (4.76%) did not meet the criterion, resulting in a sensitivity of 95.24%. The EULAR/ACR criteria scores was positively correlated with SLE disease activity index scores. Additionally, we noticed that a significant difference in clinical and immunological manifestations between HS and LS group. We observed a higher proportions of class Ⅲ or Ⅳ LN and lower proportions of class Ⅱ or V LN (p=0.034) and pathological higher activity index in HS group (p=0.007). Compared with LS groups, patients involved more severe renal damage and achieved higher rate of complete remission in the HS group. The Kaplan-Meier exploratory analyses, adjusted for LN classification, estimated glomerular filtration rate, activity index and chronicity index and induction and maintenance treatments, showed that patients in the HS group had a tendency of higher renal flare risk than that in the LS group (HR=0.21, p=0.04).

Conclusions

The EULAR/ACR criteria performed high sensitivity in identifying SLE in this cohort of biopsy-confirmed LN. Patients with LN with high criteria scores had more extrarenal manifestations, and worse renal prognosis in the short and long terms.

The predictive value of crescents in the disease progression of lupus nephritis based on the 2018 International Society of Nephrology/Renal Pathology Society Revision System: a large cohort study from China

Objective

This study analyzed the associations of different crescents’ fraction and clinical features in a Chinese lupus nephritis cohort based on the 2018 revision of ISN/RPS classification system.

Methods

A total of 288 lupus nephritis patients with complete clinicopathological data and well follow-up was enrolled. The fraction of glomeruli with cellular or fibrocellular crescents based on the new system was reevaluated. The association between crescents fractions and the outcomes were further analyzed.

Results

The median follow-up period was 76.5 months. Cellular or fibrocellular crescents were present in 146 (50.7%) of the total individuals. The percentage of crescents were significantly associated with severe clinical renal injury indices and other renal pathological parameter. According to the survival receiver operating characteristic (survival ROC) curve, the optimal cutoff level of cellular or fibrocellular crescents for predicting the composite events was 7.39%. By multivariable Cox hazard analysis, the presence of crescents was predictive of survival from the composite events with a hazard ratio [HR] of 2.5 (95% CI 1.190–5.431; p = .02). Furthermore, when we used absent, present in less than 7.39% of glomeruli, and present in greater than or equal to 7.39% of glomeruli as cutoffs in all the patients, a gradation appeared, with adjusted HRs of 2.9 (95% CI 1.326–6.313; p = .008) for crescents in greater than or equal to 7.39% of glomeruli, in reference to no crescents.

Conclusion

We proposed that the crescents were not uncommon and had important clinical significance in lupus nephritis. The cutoff point of crescents as prognosticator might be nearly 7.39%.

Renal Survival in Children with Glomerulonephritis with Crescents: A Pediatric Nephrology Research Consortium Cohort Study

There is no evidence-based definition for diagnosing crescentic glomerulonephritis. The prognostic implications of crescentic lesions on kidney biopsy have not been quantified. Our objective was to determine risk factors for end-stage kidney disease (ESKD) in patients with glomerulonephritis and crescents on kidney biopsy. A query of the Pediatric Nephrology Research Consortium’s Pediatric Glomerulonephritis with Crescents registry identified 305 patients from 15 centers. A retrospective cohort study was performed with ESKD as the primary outcome. Median age at biopsy was 11 years (range 1–21). The percentage of crescents was 3–100% (median 20%). Etiologies included IgA nephropathy (23%), lupus (21%), IgA vasculitis (19%) and ANCA-associated GN (13%), post-infectious GN (5%), and anti-glomerular basement membrane disease (3%). The prevalence of ESKD was 12% at one year and 16% at last follow-up (median = 3 years, range 1–11). Median time to ESKD was 100 days. Risk factors for ESKD included %crescents, presence of fibrous crescents, estimated GFR, and hypertension at biopsy. For each 1% increase in %crescents, there was a 3% decrease in log odds of 1-year renal survival (p = 0.003) and a 2% decrease in log odds of renal survival at last follow-up (p < 0.001). These findings provide an evidence base for enrollment criteria for crescentic glomerulonephritis in future clinical trials.

Outcome of biopsy-proven lupus nephritis with low glomerular filtration rate at presentation

OBJECTIVES

Currently, there is limited data regarding the outcomes of lupus nephritis (LN) with moderate to severe renal failure at presentation (defined by low glomerular filtration rate; GFR <30 mL/min).

METHODS

Sixty-four patients with biopsy-proven LN and estimated GFR (eGFR) <30 mL/min were prospectively analyzed. Outcome measure of persistently low eGFR, end-stage renal disease (ESRD) or death at 365 days were grouped as Major Adverse Kidney Events (MAKE365).

RESULTS

Diagnosis of lupus was simultaneous with onset of renal disease in 60% of cases. Histologically, 82.3% (n = 51) were class IV, the median serum creatinine was 4 mg/dL (interquartile range [IQR] 3.1-5.9 mg/dL), median eGFR was 13.75 mL/min (IQR 9.25-19 mL/min) and 42.2% (n = 27) required dialysis at presentation. Induction regimens included National Institute of Health (68.2%), Eurolupus protocol (10.9%) and mycophenolate mofetil (8%). Over 365 days, 23 (37.5%) subjects died, while 41 (62.5%) survived. The majority of deaths were due to infection and sepsis (14/23). Among the survivors, 70.7% had good renal outcome, 12.1% had persistently low GFR (<30 mL/min), while 17% developed ESRD. In this group, treatment response rate was 84.6% (complete response 25.6%, partial response 59%). Those with a better renal function at presentation had a good treatment response (100% vs. 40%). Altogether, n = 35 (54.6%) were included in the MAKE365 category. Between the renal survival group (n = 29) versus the MAKE365 group (n = 35) there was no difference in clinical or histological parameters.

CONCLUSION

The current treatment protocols had a good response rate in patients with LN even with severe kidney injury at presentation. However, the risk of serious infections and subsequent mortality was high.

Long-term predictive value of acute kidney injury classification in diffuse proliferative lupus nephritis with acute kidney injury

Background

The long-term predictive ability of acute kidney injury (AKI) classification based on “Kidney Disease: Improving Global Outcomes”(KDIGO) AKI diagnosis criteria has not been clinically validated in diffuse proliferative lupus nephritis (DPLN) patients with AKI. Our objective was to assess the long-term predictive value of KDIGO AKI classification in DPLN patients with AKI.

Methods

Retrospective cohort study was conducted by reviewing medical records of biopsy-proven DPLN patients with AKI from the First Affiliated Hospital of Wenzhou Medical University between Jan 1, 2000 and Dec 31, 2014. Multivariate Cox regression and survival analysis were performed.

Results

One hundred sixty-seven DPLN patients were enrolled,82(49%) patients were normal renal function (No AKI), 40(24%) patients entered AKI-1 stage (AKI-1), 26(16%) patients entered AKI-2 stage (AKI-2) and 19(16%) patients entered AKI-3 stage (AKI-3). The mean follow-up of all patients was 5.1 ± 3.8 years. The patient survival without ESRD of all patients was 86% at 5 years and 79% at 10 years. The patient survival rate without ESRD at 10 yr was 94.5% for No AKI patients, 81.8% for AKI-1 patients, 44.9% for AKI-2 patients and 14.6% for AKI-3 patients. The area under the ROC curve for KDIGO AKI classification to predict the primary end point was 0.83 (95% CI: 0.73–0.93) (P < 0.001). In Cox regression analysis, AKI stage was independently associated with primary endpoint, with an adjusted hazard ratio (HR) of 3.8(95% CI 2.1–6.7, P < 0.001).

Conclusion

Severity of AKI based on KDIGO AKI category was associated with progression to ESRD in DPLN patients. Analytical data also confirmed the good discriminative power of the KDIGO AKI classification system for predicting long-term prognosis of DPLN patients with AKI.

Efficacy of corticosteroids in immunoglobulin A nephropathy with less than 25% crescents

BACKGROUND

Crescent formation in immunoglobulin A nephropathy (IgAN) has been demonstrated to be a risk factor for worse outcomes. For IgAN patients with 0-25% crescentic glomeruli (C1), whether corticosteroids (CS) can improve the prognosis remains unclear. We tried to investigate the need for using CS in IgAN patients with C1 in different proteinuria levels.

METHODS

A total of 120 eligible IgAN patients with C1 from two academic medical centers were retrospectively studied, and 57 (47.5%) received CS. Patients were grouped according to with or without CS. The outcomes were the rate of estimated glomerular filtration rate (eGFR) decline (ml/min per 1.73 m²/year) and a composite outcome (50% decrease in eGFR, end stage renal disease (ESRD) or death due to kidney disease). The progression of adverse outcome among them were analyzed in Kaplan-Meier curve. The independent significance of CS on renal outcome or eGFR decline rate were analyzed by multivariable Cox regression or linear regression.

RESULTS

Unadjusted Kaplan-Meier showed that the outcome of treated patients was better than that of the untreated patients. Multiple Cox regression and linear regression analysis found that CS independently protected the renal outcome and decreased the eGFR decline rate. In the subgroup analysis, multivariate linear regression showed that CS decreased the eGFR decline rate both in proteinuria ≥ 1 g/day and < 1 g/day.

CONCLUSIONS

CS protected the renal outcome and slowed the eGFR decline rate of IgAN patients with C1, it also decreased the eGFR decline rate even in those with initial proteinuria < 1 g/day.

Podocyte Injury in Lupus Nephritis

Systemic lupus erythematosus (SLE) is characterized by a broad spectrum of renal lesions. In lupus glomerulonephritis, histological classifications are based on immune-complex (IC) deposits and hypercellularity lesions (mesangial and/or endocapillary) in the glomeruli. However, there is compelling evidence to suggest that glomerular epithelial cells, and podocytes in particular, are also involved in glomerular injury in patients with SLE. Podocytes now appear to be not only subject to collateral damage due to glomerular capillary lesions secondary to IC and inflammatory processes, but they are also a potential direct target in lupus nephritis. Improvements in our understanding of podocyte injury could improve the classification of lupus glomerulonephritis. Indeed, podocyte injury may be prominent in two major presentations: lupus podocytopathy and glomerular crescent formation, in which glomerular parietal epithelial cells play also a key role. We review here the contribution of podocyte impairment to different presentations of lupus nephritis, focusing on the podocyte signaling pathways involved in these lesions.

Delayed lupus nephritis in the course of systemic lupus erythematosus is associated with a poorer treatment response: a multicentre, retrospective cohort study in Japan

Objective

The objective of this study was to investigate possible differences in treatment responses between two categories for the onset of lupus nephritis.

Methods

We performed a multicentre, retrospective cohort study of class III–V lupus nephritis patients diagnosed between 1997 and 2014. The renal responses to initial induction therapy were compared between patients who developed lupus nephritis within one year from diagnosis of systemic lupus erythematosus (early (E-) LN) and the remainder (delayed (D-) LN) using the Kaplan–Meier method. We determined the predictors of renal response as well as renal flares and long-term renal outcomes using multivariate Cox regression analyses.

Results

A total of 107 E-LN and 70 D-LN patients were followed up for a median of 10.2 years. Log-rank tests showed a lower cumulative incidence of complete response in D-LN compared with E-LN patients. Multivariate analysis identified D-LN (hazard ratio (HR) 0.48, 95% confidence interval (CI) 0.33–0.70), nephrotic syndrome at baseline, and a chronicity index greater than 2 as negative predictors of complete response. D-LN patients were more likely to experience renal flares. D-LN (HR 2.54, 95% CI 1.10–5.83) and decreased renal function were significant predictors of chronic kidney disease at baseline.

Conclusion

D-LN was a predictor of poorer treatment outcomes, in addition to renal histology and severity of nephritis at lupus nephritis onset.

MicroRNA expression profile of urinary exosomes in Type IV lupus nephritis complicated by cellular crescent

Background

Type IV lupus nephritis (LNIV) is a severe disease characterized by diffuse proliferative lesions, and its prognosis is worse with cellular crescent (LNIV-CC) involvement. Urinary exosomes have been shown to reflect the degree of kidney injury. This study was aimed to identify non-invasive diagnostic markers for LNIV-CC. We analysed the expression profile of microRNAs (miRNAs) isolated from urinary exosomes in patients with LNIV-CC and LNIV, and healthy individuals using high-throughput sequencing.

Results

A total of 66 differentially expressed miRNAs were identified, which were significantly enriched in 15 signalling pathways. Bioinformatic analysis revealed a co-expression network of miRNAs, predicted transcription factors and target mRNAs. Expression of three miRNAs including miR-3135b, miR-654-5p, and miR-146a-5p were further analysed and validated by reverse transcription-quantitative polymerase chain reaction. ROC analysis suggested these as candidate biomarkers for LNIV-CC.

Conclusions

LNIV-CC has a unique miRNA expression profile of urinary exosome and complex regulatory network. miR-3135b, miR-654-5p and miR-146a-5p in urinary exosomes could be used as novel non-invasive diagnostic markers for LNIV-CC.